Cell for fuel cell and fuel cell comprising such a cell

Abstract

The invention relates to a cell (2) for a fuel cell (1), comprising: a first plate (100) comprising a peripheral region (102); a membrane electrode assembly (200) overlaid on the first plate and including a peripheral portion (202) and at least one gas diffusion layer (205) interposed between a polymer proton exchange membrane (204) and the first plate; and a first peripheral seal (300) providing a seal for the reactant fluid between, on the one hand, a bypass region (50) of the cell, and, on the other hand, a region outside the cell, the seal comprising a body portion (301) and at least one fin (302) extending into the bypass region, the fin further includes an end portion (306) interposed between the gas diffusion layer and the peripheral region and an intermediate portion (305) skewed relative to the body portion.

Description

Technical Field

[0001] The present invention relates to a cell for a fuel cell and a fuel cell comprising the cell. Background Art

[0002] US8003273B2 describes a fuel cell and at least one sealing member for use therein. The cell comprises: a membrane electrode assembly including a gas diffusion layer; and two separators on either side of the membrane electrode assembly, each separator including a flow region with a gas flow channel. Each sealing member extends from the inner surface of the annular seal and extends between the separator and the electrolyte membrane, contacting the surface of the membrane electrode assembly, and in particular the gas diffusion layer, thereby restricting the flow of gas into a bypass region. This bypass region is often referred to as a "bypass region." It may be desirable to restrict the flow of gas in the bypass region because the gas would then bypass the flow region without reacting, thereby reducing the efficiency of the cell.

[0003] In this known cell, a seal is interposed between the peripheral region of the separator and the membrane electrode assembly. The peripheral region is at the same level as the flow region, while the gas flow channels are recessed grooves in the separator. However, it may be more advantageous to provide a pressed sheet metal separator, which may mean that the bypass region extends partially beneath the gas diffusion layer. In this case, the known cell seal may not be sufficiently effective in blocking gas flow in the bypass region. Summary of the Invention

[0004] The object of the present invention is to remedy the above-mentioned drawbacks by providing a peripheral seal which blocks the flow of gas more effectively.

[0005] To this end, the present invention relates to a peripheral seal for a cell of a fuel cell, the peripheral seal comprising:

[0006] a main body portion configured to be interposed between:

[0007] The peripheral region of the plates belonging to the battery, the plates extending parallel to the main plane of the battery, the main plane being perpendicular to the stacking direction, the plates including the flow field for the reactant fluids enclosed by the peripheral region, and

[0008] ◆Belongs to the peripheral part of the membrane electrode assembly, the membrane electrode assembly also includes at least one gas diffusion layer,

[0009] • At least one fin, the at least one fin comprising an engagement portion via which the fin is attached to the body portion.

[0010] According to the present invention, the at least one fin further comprises:

[0011] an end portion of the terminating fin, the end portion being configured to be interposed between the gas diffusion layer and the peripheral region in the stacking direction, and

[0012] • Connecting the engagement portion to an intermediate portion of the end portion, the intermediate portion being configured to be deflected relative to the main body portion of the peripheral seal in projection onto the principal plane.

[0013] The idea behind the present invention is to block the flow of reactant fluid between the gas diffusion layer and the peripheral area of ​​the plate by inserting fins (in this case, the end portions of the fins) between the gas diffusion layer and the peripheral area. In this way, even when the reactant fluid is partially flowing under the gas diffusion layer, the fins can block the flow of reactant fluid, thereby increasing the proportion of reactant fluid in the flow field and thus improving the efficiency of the battery. In addition, due to the deflection of the middle portion of the fin relative to the main portion, despite the fact that the end portions of the fins are inserted (possibly compressed) between the gas diffusion layer and the peripheral area of ​​the plate, this also reduces the risk of the main portion of the first peripheral seal being laterally deformed under the tension applied by the fins. In particular, the main tension generated by the compression of the end portion by the gas diffusion layer is converted into torsional and / or bending forces at the middle portion, which deforms the middle portion. Therefore, the main portion is subjected to a resultant force much lower than the main tension, which is insufficient to deform the main portion or only slightly deforms the main portion. The first peripheral seal is then sealed off from the outside of the stack, allowing the battery to operate correctly.

[0014] The peripheral seal may comprise the following features, alone or in any technically feasible combination:

[0015] The peripheral seal comprises a plurality of fins, each fin being connected to the main body portion only via a joining portion.

[0016] The engagement portion is configured to extend perpendicularly to the main body portion in a projection onto the main plane.

[0017] The end portion is configured to extend perpendicularly to the main portion in a projection onto the main plane.

[0018] At least one of the end portion, the middle portion and the joining portion is configured as a straight line in projection onto the main plane.

[0019] A portion of the fin is configured to be curved in projection onto the main plane.

[0020] - The engagement portion has an opening that allows fluid to flow through the fin.

[0021] The main body of the peripheral seal and the fins are formed as a single piece.

[0022] The peripheral seal further includes a dam parallel to the main body portion, the dam connecting end portions of the plurality of fins, the dam being integrally formed with the first peripheral seal and configured to be interposed between the gas diffusion layer and the electrode plate along the stacking direction.

[0023] The present invention also relates to a battery for a fuel cell, the battery comprising a plate and a peripheral seal, the plate comprising:

[0024] peripheral areas, and

[0025] The reactant fluid flow field is surrounded by the peripheral area.

[0026] The battery may include the following features, alone or in any technically feasible combination:

[0027] -The battery also includes:

[0028] a membrane electrode assembly extending parallel to the main plane of the cell, superposed on the first electrode plate in the stacking direction, and comprising:

[0029] ◆The peripheral portion, which is opposite to the peripheral area in the stacking direction,

[0030] a central portion comprising a polymeric proton exchange membrane flanked by peripheral portions, and

[0031] The at least one gas diffusion layer is interposed between the polymer proton exchange membrane and the electrode plate in the stacking direction,

[0032] The peripheral seal provides: a seal against reactant fluid between: on the one hand, a bypass region of the cell, which is defined inside the cell between the peripheral portion of the membrane electrode assembly and the peripheral region, and on the other hand, a region outside the cell, which is outside the main portion and opposite the bypass region; and said at least one fin extending into the bypass region.

[0033] The contact portion of the end portion is compressed between the gas diffusion layer and the peripheral region.

[0034] The flow field defines a plurality of channels for the flow of reactant fluids, the channels extending in a longitudinal direction perpendicular to the stacking direction, each channel being defined by:

[0035] the channel bottom, which belongs to the flow field and extends parallel to the longitudinal direction, and

[0036] Two channel teeth belonging to the flow field and extending parallel to the longitudinal direction, the channel teeth being arranged on both sides of the channel bottom and protruding from the channel bottom, each channel tooth being in contact with the gas diffusion layer in the stacking direction.

[0037] The channel teeth also protrude from the peripheral area in the stacking direction.

[0038] The invention also relates to a fuel cell comprising cells, at least one of which is a cell as described above, the cells being stacked along a stacking direction to form a stack.

[0039] The present invention also aims to remedy the aforementioned drawbacks of the prior art by providing a new fuel cell which, despite having a bypass region extending below the gas diffusion layer, has an increased efficiency without affecting the sealing of the cell to the outside.

[0040] To this end, the present invention also relates to a cell for a fuel cell, comprising: a first electrode plate extending parallel to a principal plane of the cell, the principal plane being perpendicular to the stacking direction of the fuel cell; the first electrode plate including a peripheral region and a reactant fluid flow field surrounded by the peripheral region; and a membrane electrode assembly extending parallel to the principal plane of the cell, superimposed on the first electrode plate in the stacking direction, and comprising: a peripheral portion facing the peripheral region in the stacking direction; a central portion including a polymer proton exchange membrane and flanked by the peripheral portion; and at least one gas diffusion layer interposed between the polymer proton exchange membrane and the first electrode plate in the stacking direction. The cell further comprises: a first peripheral seal including a main body portion interposed between the peripheral region and the peripheral portion of the membrane electrode assembly in the stacking direction, the first peripheral seal providing a seal for the reactant fluid between: on the one hand, a bypass region of the cell defined inside the cell between the peripheral portion of the membrane electrode assembly and the peripheral region, and on the other hand, a region outside the cell, the region being outside the main body portion and opposite the bypass region; and at least one fin extending into the bypass region, the at least one fin including a joining portion via which the fin is attached to the main body portion. The fin further comprises: an end portion interposed between the gas diffusion layer and the peripheral region in the stacking direction; and an intermediate portion connecting the joining portion to the end portion, the intermediate portion being tilted relative to the main body portion of the first peripheral seal in projection onto the principal plane.

[0041] One idea behind this type of battery is to block the flow of reactant fluid between the gas diffusion layer and the peripheral area of ​​the plate by inserting fins between the gas diffusion layer and the peripheral area. In this way, even when the bypass area extends partially under the gas diffusion layer, the fins can block the flow of reactant fluid, thereby increasing the proportion of reactant fluid in the flow field and thus improving the efficiency of the battery. In addition, due to the deflection of the middle part of the fin relative to the main part, despite the fact that the end part of the fin is inserted (possibly compressed) between the gas diffusion layer and the peripheral area of ​​the plate, this also reduces the risk of the main part of the first peripheral seal being laterally deformed under the tension applied by the fin. In particular, the main tension generated by the compression of the end part by the gas diffusion layer is converted into torsional and / or bending forces at the deflected part, which deforms the deflected part. Therefore, the main part is subjected to a resultant force much lower than the main tension, which is insufficient to deform the main part or only slightly deforms the main part. The first peripheral seal is then sealed off from the outside of the stack, allowing the battery to operate correctly.

[0042] The batteries of the present disclosure may include the following features, alone or in any technically feasible combination:

[0043] The engagement portion extends perpendicularly to the main portion of the first peripheral seal in projection onto the main plane.

[0044] The end portion extends perpendicularly to the main portion of the first peripheral seal in projection onto the main plane.

[0045] - At least one of the end portion, the middle portion and the joining portion is projected onto the main plane as a straight line.

[0046] A portion of the fin is curved, this portion protruding into the main plane.

[0047] The contact portion of the end portion is compressed between the gas diffusion layer and the peripheral region.

[0048] - The engagement portion has an opening that allows fluid to flow through the fin.

[0049] The battery further includes a dam parallel to the main body, connecting end portions of the plurality of fins and interposed between the gas diffusion layer and the first electrode plate in the stacking direction, the dam being formed as a whole with the first peripheral seal.

[0050] The main portion of the first peripheral seal and the fin are formed as a single piece.

[0051] The flow field defines a plurality of channels for the flow of the reactant fluid, the channels extending in a longitudinal direction perpendicular to the stacking direction, each channel being defined by: a channel bottom belonging to the flow field and extending parallel to the longitudinal direction, and two channel teeth belonging to the flow field and extending parallel to the longitudinal direction, the channel teeth being arranged on both sides of the channel bottom and protruding relative to the channel bottom, each channel tooth being in contact with the gas diffusion layer in the stacking direction.

[0052] The channel teeth also protrude from the peripheral area in the stacking direction.

[0053] The membrane electrode assembly comprises a holding frame which forms the peripheral portion and which forms the sides of the central portion.

[0054] The battery further comprises: a second electrode plate located outside the membrane electrode assembly opposite to the first electrode plate in the stacking direction; and a second peripheral seal interposed between the second electrode plate and the membrane electrode assembly in the stacking direction.

[0055] The present disclosure also relates to a fuel cell comprising cells, at least one of which is a cell as described above, the cells being stacked along a stacking direction to form a stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The invention will be better understood on reading the following description, given by way of example only, and with reference to the accompanying drawings, in which:

[0057] -[ Figure 1 ] Figure 1 is an exploded view of a portion of a fuel cell according to a first embodiment of the present invention.

[0058] -[ Figure 2 ] Figure 2 is included Figure 1 A cross-sectional view of a portion of a fuel cell stack with cells in it.

[0059] -[ Figure 3 ] Figure 3 yes Figure 1 Another cross-sectional view of a portion of a battery in FIG.

[0060] -[ Figure 4 ] Figure 4 is a top view of a portion of the battery of the previous figure, showing Figure 2 Section II-II' and Figure 3 Section III-III'.

[0061] -[ Figure 5 ] Figure 5 is with Figure 2 A similar cross-sectional view in which the stack is shown in an unassembled state.

[0062] -[ Figure 6 ] Figure 6 is a cross-sectional view of a portion of a stack including a battery according to a second embodiment of the present invention.

[0063] -[ Figure 7 ] Figure 7 yes Figure 6 A top view of a portion of a battery, showing Figure 6 Section IV-IV' in the figure.

[0064] -[ Figure 8 ] Figure 8 is a top view of a portion of a battery according to a third embodiment of the present invention.

[0065] -[ Figure 9 ] Figure 9 is a cross-sectional view of a portion of a stack including a battery according to a fourth embodiment of the present invention.

[0066] -[ Figure 10 ] Figure 10 yes Figure 9 A top view of a portion of a battery, showing Figure 9 Section V-V' in.

[0067] -[ Figure 11 ] Figure 11 FIG. 1 is a top view of a fifth embodiment of the present invention.

[0068] -[ Figure 12 ] Figure 12 is a cross-sectional view of a portion of a stack including a battery according to a sixth embodiment of the present invention.

[0069] -[ Figure 13 ] Figure 13 yes Figure 12 A top view of a portion of a battery, showing Figure 12 Section VI-VI' in.

[0070] -[ Figure 14 ] Figure 14 is a cross-sectional view of a portion of a stack including a battery according to a seventh embodiment of the present invention.

[0071] -[ Figure 15 ] Figure 15 is a cross-sectional view of a portion of a battery according to an eighth embodiment of the present invention.

[0072] -[ Figure 16 ] Figure 16 is a cross-sectional view of a portion of a battery according to a ninth embodiment of the present invention.

[0073] -[ Figure 17 ] Figure 17 is a top view of a ninth embodiment of the present invention, showing Figure 16 Section VIII-VIII'. DETAILED DESCRIPTION

[0074] Figures 1 to 5 A first embodiment according to the present invention is shown.

[0075] Figure 1 The figure shows a first electrode plate (called cathode electrode plate) 100 and an electrode membrane assembly 200 forming part of a cell 2 of a fuel cell 1. The cell 2 also has a second electrode plate (called anode electrode plate) 100', as shown in FIG. Figure 2 shown.

[0076] The cathode plate 100 is perpendicular to the stacking direction X of the fuel cell 1. Figure 2 As shown, the stacking direction points upward. The cathode plate 100 extends parallel to the main plane P of the battery 2 and perpendicular to the stacking direction X. It is also defined that Figure 2 The longitudinal direction Y oriented toward the front and Figure 2 A transverse direction Z is oriented from left to right in the stacking direction, the two directions extending in the main plane P, perpendicular to each other and perpendicular to the stacking direction X.

[0077] The cathode plate 100 may be formed of a conductive material, for example a metal such as stainless steel or graphite. The cathode plate 100 has a peripheral region 102 , an opening 101 , two averaging fields 104 and a flow field 103 .

[0078] The peripheral region 102 extends all the way around the cathode plate 100 and adjoins the opening 101, the homogenizing field 104, and the flow field 103. The opening 101, the homogenizing field 104, and the flow field 103 are arranged inside the peripheral region 102. The peripheral region 102 extends in a plane perpendicular to the stacking direction X and parallel to the main plane P.

[0079] The flow field 103 extends between the two averaging fields 104 in the longitudinal direction Y. On the side of the cathode plate 100 facing the membrane electrode assembly 200, i.e., along the stacking direction X, the flow field 103 comprises a channel 105, which is formed as a recess and extends substantially parallel to the longitudinal direction Y. The channel 105 can be defined by a groove cut into the cathode plate 100 or by stamping the cathode plate 100.

[0080] Each channel 105 is defined in depth along the stacking direction X by a channel bottom 1051 formed by the cathode plate 100 extending along the longitudinal direction Y. The channel bottom 1051 may be substantially flat, as shown in simplified form in the figure, but typically has a slightly rounded profile in cross-section through a transverse plane containing the transverse direction Z. In certain embodiments, such as for example Figure 2 and Figure 3 In the embodiment shown in , the channel bottom 1051 is coplanar with the peripheral region 102 at least at its point of maximum channel depth along the stacking direction X. Alternatively, the channel bottom 1051 is set back in the stacking direction X relative to the peripheral region 102 .

[0081] Each channel 105 is further delimited by two channel teeth 1052 formed by the cathode plate 100 and projecting from the channel bottom 1051 in the stacking direction X. Preferably, the channel teeth 1052 also project from the peripheral region 102 in the stacking direction X. The channel teeth 1052 are substantially flat and parallel to the channel bottom 1051. Alternatively, the channel teeth 1052 have a slightly rounded profile in a cross-section through a transverse plane containing the transverse direction Z and the stacking direction X. The channel teeth 1052 abut the channel bottom 1051 along its length in the longitudinal direction Y.

[0082] The channel bottom 1051 is continuously connected to each channel tooth 1052 through an inclined portion 1053 formed by the cathode plate 100. Therefore, the channel 105 is also defined by two inclined portions 1053.

[0083] For each cell 2 of the fuel cell 1, each opening 101 is intended to be used to inject a reaction fluid or a cooling fluid, or to drain a reaction fluid or a cooling fluid. These openings 101 have a closed perimeter. Three openings 101 are located on one side of the cathode plate 100 in the longitudinal direction Y and aligned in the transverse direction Z; the other three openings 101 are located on the other side of the cathode plate 100 in the longitudinal direction Y and also aligned in the transverse direction Z. For each reaction fluid or cooling fluid, and therefore for each fluid flow field of the cell, one opening 101 forms a fluid supply for the relevant flow field, and another opening 101 located on the other side of the cathode plate 100 in the longitudinal direction Y is used to discharge the fluid for the relevant flow field.

[0084] Each equalization field 104 is arranged between the flow field 103 and the opening 101 in the longitudinal direction Y. On the side of the cathode plate 100 facing the membrane electrode assembly 200, that is, in the stacking direction X, each equalization field 104 may include channels, which are arranged, for example, in a fan-shaped orientation. These channels connect one of the openings 101 to the flow field 103. As in the example shown, the channels of the equalization field 104 can be similar to the channels of the flow field 103 and formed in the same way, except for their orientation. However, the channels of the equalization field 104 can have, for example, a different width and / or depth than the channels of the flow field 103. Similarly, the channels in the equalization field 104 can also be produced differently from the channels in the flow field 103, in particular using different technical processes. The channels of the homogenization field 104 can be produced, for example, in the form of ribs (which may or may not be flat) applied by adding metal, elastomer or polymer material to parts of the cathode plate 100, while the channels 105 of the flow field 103 can be produced by stamping, or vice versa.

[0085] For the cathode plate 100, the first homogenizing field 104 distributes the reactant fluid from one of the openings 101b so that it flows throughout the flow field 103 in the longitudinal direction Y. The second homogenizing field 104 allows the reactant fluid distributed throughout the flow field 103 to be discharged to another opening 101b located at a position opposite to the cathode plate 100, where the reactant fluid is discharged. Therefore, on the face of the cathode plate 100 facing the membrane electrode assembly 200, only one of the reactant fluids flows from one of the openings 101 through the flow field 103 to the other opening of the openings 101 opposite in the longitudinal direction Y. For the cathode plate 100, the reactant fluid is the cathode reactant fluid, such as air or oxygen. The intent is that only opening 101b delivers and drains fluid to that face of cathode plate 100 , while the perimeter of openings 101a and 101c is sealed so that fluid passing through openings 101a and 101c does not contact the cathode reactant fluid on that face of cathode plate 100 .

[0086] The membrane electrode assembly (MEA) 200 faces the cathode plate 100 in the stacking direction X and is parallel to the main plane P. The MEA 200 includes a peripheral portion 202 , an opening 201 , and a central portion 203 .

[0087] The peripheral portion 202 extends all around the MEA 200 and adjoins the opening 201 and the central portion 203 located inside the peripheral portion 202. The opening 201 has a closed perimeter. The peripheral portion 202 extends in a plane perpendicular to the stacking direction X and parallel to the main plane P.

[0088] Openings 201 are made in the membrane electrode assembly (MEA) 200 to allow reactant fluid to flow through the MEA in the stacking direction X. Each opening 201 extends one of the openings 101 in the cathode plate 100 in the stacking direction X. In other words, the openings 101 and 201 face each other in the stacking direction X. In this example, each opening 201 has the same shape as the opening 101 it faces.

[0089] The central portion 203 of the MEA 200 faces the flow field 103 and completely covers the flow field 103 in the stacking direction X. The outer peripheral edge of the central portion 203 may overlap with the inner edge of the outer peripheral portion 202 .

[0090] The central portion 203 of the MEA 200 includes a membrane 204, which is a polymeric proton exchange membrane. The membrane 204 extends parallel to the main plane P, faces the flow field 103 in the stacking direction X, and is substantially flat. The membrane 204 is preferably coplanar with the peripheral portion 202. The membrane 204 may be covered with a catalyst layer on one or both of its faces parallel to the main plane P. Figure 2 As shown, the membrane 204 may potentially extend beyond the flow field 103 , particularly where the central portion 203 overlaps a portion of the peripheral portion 202 .

[0091] The MEA 200 advantageously comprises a holding frame 206 for supporting the membrane 204. The holding frame 206 then forms the peripheral portion 202. The holding frame 206 is preferably composed of two half-frames of identical shape, intended to lie flat against each other and made, for example, of a polymer film such as polyethylene terephthalate (abbreviated PET) or polyethylene naphthalate (abbreviated PEN). In the latter case, for example, the two half-frames are glued together. Figure 2 、 Figure 3 and Figure 5 As shown, in order to hold the membrane 204, the holding frame 206 can clamp in particular the outer peripheral edge of the membrane 204 in the stacking direction X. The holding frame 206 then grips the entire portion of the membrane 204 that overlaps the peripheral portion 202 in the stacking direction X. The holding frame 206 thus has a central opening, the perimeter of which, where appropriate, delimits the central portion 203 of the MEA 200, through which the membrane 204 can access the reactant fluid flowing in the flow field.

[0092] Alternatively, rather than retaining frame 206 , a single membrane, such as membrane 204 , may form both central portion 203 and peripheral portion 202 .

[0093] The gas diffusion layer 205 extends parallel to the main plane P. It is interposed between the central portion 203 and the cathode plate 100 in the stacking direction X. In particular, the gas diffusion layer 205 completely covers the central portion 203, i.e., the membrane 204, and advantageously overhangs the peripheral portion 202, i.e., the inner periphery of the retaining frame 206, which holds the membrane 204. In particular, the gas diffusion layer 205 rests on the channel teeth 1052 of the channels 105 in the stacking direction X and abuts against the membrane 204 in the opposite direction. The gas diffusion layer 205 is advantageously formed of a porous material and, when the cell 2 is in operation, allows the cathode reactant fluid to diffuse from the channels 105 toward the membrane 204, and may also allow reaction products from the membrane 204 to diffuse into the channels 105 for removal.

[0094] The cell 2 includes a first peripheral seal 300 interposed between the cathode plate 100 and the MEA 200 along the stacking direction X. The peripheral seal 300 includes a main body portion 301 and fins 302 .

[0095] The first peripheral seal 300 may be formed on the cathode plate 100, for example, as Figure 1 2. The cathode plate 100 is shown as being overmolded onto the MEA 200, but it may alternatively be formed on the MEA 200, or formed separately from the cathode plate 100 and the MEA 200 and then assembled to either of these by any means known to the skilled person. The first peripheral seal 300 is desirably made of an elastomeric material, such as silicone or EPDM, and is impermeable to the cathode fluid used in the fuel cell 1.

[0096] The first peripheral seal 300 includes a main body portion 301 and at least one (preferably a plurality) of fins 302. Preferably, each of the several fins 302 is separate, i.e., it is only connected to the main body portion 301 and not to, for example, another fin 302. In particular, the fins 302 are spaced apart.

[0097] The main body portion 301 forms a closed loop that, in this example, extends all the way around the cathode plate 100 along the peripheral region 102. Accordingly, the main body portion 301 extends in a closed loop along the peripheral portion 202 of the MEA 200 (here, along the retaining frame 206) around the entire periphery of the peripheral portion 202. The main body portion 301 is interposed between the peripheral region 102 and the peripheral portion 202 in the stacking direction X to seal the space defined all the way around between the peripheral region 102 and the peripheral portion 202 in the stacking direction X. In particular, the main body portion 301 surrounds the flow field 103, the homogenization field 104 (if provided), the opening 101b for that face of the cathode plate 100, or even potentially all openings 101 of the cathode plate 100. The main body portion 301 also surrounds the gas diffusion layer 205, and the face of the membrane 204 facing away from the stacking direction X faces the cathode plate 100. The main body portion 301 includes two opposing inner longitudinal surfaces 303, each arranged transversely on either side of the flow field 103, each inner longitudinal surface 303 extending beyond a portion of the main body portion 301 that is parallel to the longitudinal direction Y and faces the direction of the flow field 103. Each inner longitudinal surface 303 connects the peripheral region 102 to the peripheral portion 202 in the stacking direction X.

[0098] The main body portion 301 of the first peripheral seal 300, the cathode plate 100 and the MEA 200 thus define a cathode compartment 40 therebetween. The main body portion 301 seals the cathode compartment 40 from the outside of the cell 2, and in particular seals the outer region 3 located outside the main body portion 301 of the first peripheral seal 300 from the cathode compartment 40.

[0099] Two cathode bypass regions 50 belonging to the cathode compartment 40 are defined. Each bypass region 50 is bounded in the stacking direction X between the cathode plate 100 and the MEA 200, and in the transverse direction Z between: the flow field 103 and the gas diffusion layer 205, on the one hand; and the main body 301 of the first peripheral seal 300, specifically, the portion of the main body 301 extending in the longitudinal direction Y, on the other hand. Each bypass region 50 extends in the longitudinal direction Y along the flow field 103 and even from one homogenization field 104 to the other. The flow field 103 is arranged in the transverse direction Z between the two bypass regions 50.

[0100] The purpose of the fins 302 is to reduce or prevent the flow of the cathode reactant fluid in the bypass region 50 in the longitudinal direction Y, in particular in order to concentrate the fluid in the flow field 103. To this end, each fin 302 closes a cross section of the bypass region 50 that it occupies, the cross section being taken perpendicular to the longitudinal direction Y. The fins 302 are distributed in one or the other or both cathode bypass regions in the cathode bypass region 50 along the main body 301 of the first peripheral seal 300. Each fin 302 is attached to one of the internal longitudinal surfaces 303 of the main body 301. Each fin 302 extends generally in the transverse direction Z from the internal longitudinal surface 303 towards the interior of the main body 301 in the direction of the flow field 103. The fins 302 may be formed as one piece with the main body 301.

[0101] Each fin 302 includes, starting from the main body portion 301 , a joining portion 304 , a middle portion 305 , and an end portion 306 .

[0102] In the example shown, each fin 302 is advantageously in the shape of a wall having a protrusion in the main plane P, the protrusion having a broken line profile, a curved profile or a profile consisting of a combination of one or more straight lines and / or one or more broken lines and / or one or more curves.

[0103] Optionally, each wall-shaped fin 302 preferably has, at any point considered in its extension, a thickness in the longitudinal direction Y (also called width) and a thickness in the stacking direction X, in a section through a plane perpendicular to the extension of the wall at this point considered, such that the thickness in the longitudinal direction Y is smaller than the thickness in the stacking direction X, in particular so as to extend from the cathode plate 100 to the MEA 200 over at least a portion of the length of the fin 302 in the transverse direction Z, or even over its entire length. Alternatively, the thickness in the longitudinal direction Y is greater than the thickness in the stacking direction X, or varies depending on the point of extension considered.

[0104] Preferably, each of the joint portion 304, the middle portion 305, and the end portion 306 has the same width, i.e., the same thickness measured in the Y direction. In other words, each of the fins 302 has a substantially constant thickness in the Y direction. This minimizes the material used to form the fins 302 and ensures proper formation of the fins 302, particularly the continuity of the material during the manufacturing process of the peripheral seal 300.

[0105] The fin 302 is connected to the body portion 301 via a joining portion 304 extending from the inner longitudinal surface 303. In particular, the fin 302 is attached to the body portion 301 via the joining portion 304 only.

[0106] In this example, the joint portion 304 is a straight line and its projection on the main plane P is perpendicular to the longitudinal direction Y, ie parallel to the transverse direction Z. The joint portion 304 is interposed along the stacking direction X between the peripheral region 102 of the cathode plate 100 and the peripheral portion 202 of the MEA 200 .

[0107] The middle portion 305 of the fin 302 is attached to the joining portion 304 so as to extend in the direction of the flow field 103. In this example, the middle portion 305 is a straight line, and its projection on the main plane P is tilted relative to the main portion 301, or tilted relative to the longitudinal direction Y. The middle portion 305 is interposed between the peripheral region 102 of the cathode plate 100 and the peripheral portion 202 of the MEA 200 along the stacking direction X.

[0108] The length of the joint portion 304 projected on the plane P is preferably smaller than the length of the middle portion of the fin 302 , for example, smaller than 50%, preferably smaller than 30%, advantageously smaller than 10% of the length of the middle portion 305 .

[0109] The end portions 306 of the fin 302 are attached to the middle portion 305 so that they extend in the direction of the flow field 103. The end portions 306 terminate the fin 302. In this example, the end portions 306 are straight lines and their projections onto the main plane P are perpendicular to the longitudinal direction Y, i.e. parallel to the transverse direction Z.

[0110] Neither the middle portion 305 nor the end portion 306 is attached to the main body portion 301 except through the joining portion 304. At least one portion of the fin 302 that belongs to the end portion 306 and includes the end of the fin 302 (referred to as the contact portion 307 of the fin 302) is interposed between the gas diffusion layer 205 and the peripheral region 102 in the stacking direction X. Optionally, the end portion 306 is interposed between the peripheral region 102 and the peripheral portion 202 through another portion of the end portion 306 that is attached to the middle portion 305.

[0111] The angle formed therebetween by the end portion 306 and the middle portion 305 is advantageously between 110 and 150 degrees, ideally 120 degrees. The angle formed by the middle portion 305 and the joining portion 304 is advantageously between 110 and 150 degrees, ideally 120 degrees.

[0112] Therefore, according to Figures 1 to 5 In the embodiment shown in , each fin 302 has an extension trajectory which, in projection on the plane P, forms a zigzag shape from the main portion 301 toward the flow field 103 .

[0113] like Figure 2 、 Figure 3 and Figure 4As shown, the contact portion 307 of the fin 302 is elastically deformed between the gas diffusion layer 205 and the peripheral region 102 in compression along the stacking direction X. When the contact portion 307 is compressed in this manner, it has a thickness measured along the stacking direction X that is less than the thickness of the remaining portion of the fin 302, in particular the thickness of the joint portion 304 and the middle portion 305. Figure 5 As shown, in the undeformed state of the fin 302, the contact portion 307 may initially be expected to have the same thickness as the rest of the fin 302 along the stacking direction X. This compressive deformation of the contact portion 307 may also cause the middle portion 305 to deform. Figure 3 As shown in the cross section in FIG, the middle portion 305 can absorb this deformation of the end portion 306 by slightly twisting. The fact that the middle portion 305 is tilted relative to the longitudinal direction Y advantageously avoids the transmission of deformation to the junction portion 304 and to the main body portion 301. Therefore, the special orientation of the middle portion 305 prevents the mechanical stress associated with the flattening of the contact portion 307 between the gas diffusion layer 205 and the peripheral region 102 from being applied to the main body portion 301.

[0114] Anode plate 100 ′ is similar to cathode plate 100 with a few differences, most of which are discussed below. Anode plate 100 ′ extends parallel to the main plane P of cell 2 , perpendicular to stacking direction X, and is positioned outside MEA 200 opposite cathode plate 100 .

[0115] Anode plate 100 ′ is advantageously formed of the same material as cathode plate 100 and, like cathode plate 100 , includes a peripheral region 102 ′ similar to peripheral region 102 , an opening similar to opening 101 , two equalizing fields similar to equalizing field 104 , and a flow field 103 ′ similar to flow field 103 .

[0116] The peripheral region 102' extends all the way around the anode plate 100' and is adjacent to the opening, the equalization field, and the flow field 103'. As with the cathode plate 100, the opening, the equalization field, and the flow field 103' of the anode plate 100' are arranged inside the peripheral region 102'. The peripheral region 102' extends in a plane perpendicular to the stacking direction X and parallel to the main plane P.

[0117] Like opening 101, each opening in anode plate 100' is used to inject or discharge reactant fluid or cooling fluid corresponding to opening 101. In stacking direction X, each opening in anode plate 100' is connected to one of openings 101 via one of openings 201 in MEA 200.

[0118] The flow field 103' extends between the two averaging fields of the plate 100' in the longitudinal direction Y. On the face of the anode plate 100' facing the membrane electrode assembly 200, i.e., in the direction opposite to the stacking direction X, the flow field 103' comprises a channel 105' formed as a recess and extending substantially parallel to the longitudinal direction Y. The channel 105' can be defined by a groove cut into the anode plate 100' or by stamping the anode plate 100'.

[0119] The depth of each channel 105' in the stacking direction X is defined by a channel bottom 1051' formed by the anode plate 100' extending in the longitudinal direction Y. The channel bottom 1051' may be substantially flat, as shown in simplified form in the figure, but typically has a slightly rounded profile in cross-section through a transverse plane containing the transverse direction Z. In some embodiments, such as Figure 2 In the embodiment shown in FIG, the channel bottom 1051 ′ is coplanar with the peripheral region 102 ′ at least at the point of the channel 105 ′ at its maximum depth along the stacking direction. Alternatively, not shown, the channel bottom 1051 ′ protrudes from the peripheral region 102 ′ in the stacking direction X.

[0120] Each channel 105' is also delimited by two channel teeth 1052' formed by the anode plate 100' and arranged rearwardly from the channel bottom 1051' in the stacking direction X. Preferably, the channel teeth 1052' are also arranged rearwardly from the peripheral region 102' in the stacking direction X. The channel teeth 1052' are substantially flat and parallel to the channel bottom 1051'. Alternatively, the channel teeth 1052' have a slightly rounded profile in a cross-section through a transverse plane containing the transverse direction Z and the stacking direction X. The channel teeth 1052' abut the channel bottom 1051' along its length in the longitudinal direction Y.

[0121] The channel bottom 1051' is continuously connected to each channel tooth 1052' through an inclined portion 1053' formed by the anode plate 100'. Therefore, the channel 105' is also defined by two inclined portions 1053'.

[0122] As with the cathode plate 100, each equalization field of the anode plate 100' is arranged between the flow field 103' and the opening of the anode plate 100' in the longitudinal direction Y and can include a channel, for example in the form of a fan. The first equalization field distributes the reactant fluid from one of the openings in the anode plate 100' so that it flows in the flow field 103', and the second equalization field allows the reactant fluid distributed over the entire flow field 103' to be discharged to the other opening. Whereas the flow field 103 of the cathode plate 100 is supplied with the cathode reactant fluid, i.e., air or oxygen, via opening 101b, the flow field 103' is supplied with the anode reactant fluid, such as hydrogen, via the opening corresponding to opening 101a in the anode plate 100'. The contours of the other openings in the anode plate 100' corresponding to openings 101b and 101c are sealed so that only the anode reactant fluid can flow within the flow field 103'.

[0123] MEA 200 includes another gas diffusion layer 205', which extends parallel to the main plane P. It is interposed between the central portion 203 of MEA 200 and the anode plate 100' in the stacking direction X. Thus, the central portion 203 of MEA 200 is interposed between the two gas diffusion layers 205 and 205' in the stacking direction X. In particular, gas diffusion layer 205' completely covers the central portion 203 of MEA 200, i.e., the membrane 204, and advantageously overhangs the peripheral portion 202, i.e., the inner periphery of the retaining frame 206, which holds the membrane 204. In particular, gas diffusion layer 205' rests on channel teeth 1052' of channels 105' in a direction opposite to the stacking direction X. Gas diffusion layer 205' is advantageously formed of a porous material and allows anode reactant fluid to diffuse from channels 105' toward membrane 204, and possibly reaction products from membrane 204 to diffuse into channels 105' for removal, when cell 2 is operating.

[0124] As the anode and cathode reactant fluids are supplied through the gas diffusion layers 205 and 205' via the flow fields 103 and 103', a chemical reaction between the reactant fluids occurs at the membrane 204 of the cell 2. By exchanging protons between the anode reactant fluid and the cathode reactant fluid across the membrane, a potential difference is generated between the cathode plate 100 and the anode plate 100'.

[0125] The cell 2 comprises a second peripheral seal 300 ′ which is preferably similar to the seal 300 and is interposed between the anode plate 100 ′ and the MEA 200 along the stacking direction X. The peripheral seal 300 ′ comprises a body portion 301 ′ and fins 302 ′ which are similar to the body portion 301 and the fins 302 .

[0126] The second peripheral seal 300' may be formed on the anode plate 100', for example by overmolding thereto, but it may alternatively be formed on the MEA 200, or formed separately from the anode plate 100' and the MEA 200. The seal 300' is desirably made of an elastomeric material and is impermeable to the anode fluid used in the fuel cell 1.

[0127] In particular, the main portion 301' of the second peripheral seal 300' forms a closed loop that, in this example, extends all the way around the anode plate 100' along the peripheral region 102'. Accordingly, the main portion 301' extends in a closed loop along the peripheral portion 202 of the MEA 200 (here, along the retaining frame 206) around the entire periphery of the peripheral portion 202. The main portion 301' is interposed between the peripheral region 102' and the peripheral portion 202 in the stacking direction X to seal the space defined all the way around between the peripheral region 102' and the peripheral portion 202 in the stacking direction X. In particular, the main portion 301' surrounds the flow field 103', the homogenization field of the anode plate 100' (if provided), the openings providing the anode fluid to that face of the anode plate 100', or all openings of the anode plate 100'. The main body portion 301′ also surrounds the faces of the gas diffusion layer 205′ and the membrane 204′ that face each other in the stacking direction X. The main body portion 301′ includes two opposing inner longitudinal surfaces 303′, each disposed transversely on either side of the flow field 103′, each inner longitudinal surface 303′ extending beyond a portion of the main body portion 301′ that faces the flow field 103′ and is parallel to the longitudinal direction Y. Each inner longitudinal surface 303′ connects the outer peripheral region 102′ to the outer peripheral portion 202 in the stacking direction X.

[0128] The main portion 301' of the second peripheral seal 300', the anode plate 100' and the MEA 200 thus define an anode compartment 40' between them. The main portion 301' of the second peripheral seal 300' seals the anode compartment 40' relative to the outside of the cell 2, in particular the outer region 3.

[0129] Two anode bypass regions 50' belonging to the anode compartment 40' are defined. Each bypass region 50' is defined between the anode plate 100' and the MEA 200 in the stacking direction X, and in the transverse direction Z between: on the one hand, the flow field 103' and the gas diffusion layer 205', and on the other hand, the main body 301' of the second peripheral seal 300', with respect to the portion of the main body 301' extending in the longitudinal direction Y. Each bypass region 50' extends along the flow field 103' in the longitudinal direction Y. The flow field 103' extends in the transverse direction Z between the two bypass regions 50'.

[0130] The function of the fin 302' is to reduce or prevent the flow of the anode reactant fluid in the bypass region 50' in the longitudinal direction Y. To this end, each fin 302' closes the cross-section of the bypass region 50' it occupies, which cross-section is taken perpendicular to the longitudinal direction Y. The fins 302' are distributed in one or the other or two anode bypass regions of the anode bypass region 50' along the main body 301' of the second peripheral seal 300'. Each fin 302' is attached to one of the internal longitudinal surfaces 303' of the main body 301' of the second peripheral seal 300'. Each fin 302' extends generally in the transverse direction Z from the internal longitudinal surface 303' toward the flow field 103'. The fin 302' can be formed as a whole with the main body 301'.

[0131] Each fin 302 ′ includes, starting from the main body portion 301 ′, a joining portion 304 ′, a middle portion 305 ′, and an end portion 306 ′.

[0132] In the example shown, each fin 302 ′ is advantageously in the shape of a wall having a projection in the main plane P having a broken line profile, a curved profile or a profile consisting of a combination of one or more straight lines and / or one or more broken lines and / or one or more curves.

[0133] Optionally, each wall-like fin preferably has, at any point considered in its extension, a thickness in the longitudinal direction Y (also called width) and a thickness in the stacking direction X, in a section through a plane perpendicular to the extension of the wall at this point considered, such that the thickness in the longitudinal direction Y is smaller than the thickness in the stacking direction X, in particular so as to extend from the anode plate 100' to the MEA 200' over at least a portion of the length of the fin 302' in the transverse direction Z or even over its entire length.

[0134] Alternatively, the thickness in the longitudinal direction Y is greater than the thickness in the stacking direction X, or varies depending on the point of the protrusion considered.

[0135] Preferably, each of the joining portion 304', the middle portion 305', and the end portion 306' has the same width, i.e., the same thickness measured in the Y direction. In other words, each of the fins 302' has a substantially constant thickness in the Y direction. This minimizes the material used to form the fins 302' and ensures proper formation of the fins 302', particularly the continuity of the material during the manufacturing process of the peripheral seal 300'.

[0136] The fin 302' is connected to the main body 301' via a joint portion 304' extending from the inner longitudinal surface 303'. In this example, the joint portion 304' is a straight line, and its projection on the main plane P is perpendicular to the longitudinal direction Y, that is, parallel to the transverse direction Z. The joint portion 304' is interposed between the peripheral region 102' of the anode plate 100' and the peripheral portion 202 of the MEA 200 along the stacking direction X.

[0137] The middle portion 305' of the fin 302' is attached to the joining portion 304' so that it extends in the direction of the flow field 103'. In this example, the middle portion 305' is a straight line, and its projection on the main plane P is tilted relative to the longitudinal direction Y. The middle portion 305' is interposed between the peripheral region 102' of the anode plate 100' and the peripheral portion 202 of the MEA 200 along the stacking direction X.

[0138] The length of the joint portion 304 ′ projected on the plane P is preferably less than the length of the middle portion of the fin 302 ′, for example less than 50%, preferably less than 30%, advantageously less than 10% of the length of the middle portion 305 ′.

[0139] The end portion 306' of the fin 302' is attached to the middle portion 305', thereby extending in the direction of the flow field 103'. The end portion 306' terminates the fin 302'. In this example, the end portion 306' is a straight line, and its projection onto the main plane P is perpendicular to the longitudinal direction Y, that is, parallel to the transverse direction Z.

[0140] At least one portion of the fin 302′ that belongs to the end portion 306′ of the fin 302′ and includes the end of the fin 302′ (referred to as a contact portion 307′) is interposed between the gas diffusion layer 205′ and the peripheral region 102′ in the stacking direction X. Optionally, another portion of the end portion 306′, through which the end portion 306′ is attached to the middle portion 305′, is interposed between the peripheral region 102′ and the peripheral portion 202.

[0141] The angle formed by the end portion 306' and the middle portion 305' is advantageously between 110 degrees and ideally 120 degrees. The angle formed by the middle portion 305' and the joining portion 304' is advantageously between 110 degrees and 150 degrees, ideally 120 degrees.

[0142] Therefore, according to Figures 1 to 4 In the embodiment shown in FIG, each fin 302 ′ has an extension trajectory which, in projection on the plane P, forms a zigzag shape from the main portion 301 ′ toward the flow field 103 ′.

[0143] like Figure 2 、 Figure 3 and Figure 4 As shown, the contact portion 307' of the fin 302' is elastically deformed between the gas diffusion layer 205' and the peripheral region 102' in compression along the stacking direction X. This compressive deformation of the contact portion 307' can also cause the middle portion 305' to deform. Figure 3 As shown in the cross-section in FIG, the middle portion 305′ can absorb this deformation of the end portion 306′ by slightly twisting. The fact that the middle portion 305′ is tilted relative to the longitudinal direction Y advantageously prevents the transmission of deformation to the junction portion 304′ and to the main portion 301′. Thus, the specific orientation of the middle portion 305′ prevents the mechanical stress associated with the flattening of the contact portion 307′ between the gas diffusion layer 205′ and the peripheral region 102′ from being applied to the main portion 301′.

[0144] In order to demonstrate the elastic deformation of the fin 302 when assembling the battery 2, Figure 5 The same battery 2 is also shown in an unassembled state. Figure 5 Before the illustrated cell, the end portions 306 and 306' of the seals 300 and 300' were not compressed between the gas diffusion layer 205 and the peripheral region 102 and between the gas diffusion layer 205' and the peripheral region 102', respectively, along the stacking direction X. The contact portions 307 and 307' had the same thickness as the rest of the fins 302 and 302'. Figure 5 Also shown are seals 300 and 300 ′ that are integral to plates 100 and 100 ′, respectively, rather than MEA 200 .

[0145] In practice, in the fuel cell 1 , several cells 2 (such as the one described above) are stacked along the stacking direction X, each cell comprising a cathode plate 100 , a first peripheral seal 300 , an MEA 200 , a second peripheral seal 300 ′ and an anode plate 100 ′.

[0146] like Figure 2 As shown, several batteries 2 are stacked one on top of the other in the stacking direction X, so that the anode plate 100' of one battery 2 abuts the cathode plate 100 of the next battery 2 in the stacking direction X, and the plates 100' and 100 of two adjacent batteries are thus superimposed in the stacking direction X. The anode plates 100' and cathode plates 100 of the two adjacent batteries 2 stacked in this way form a bipolar plate 10. In this example, the plates 100 and 100' of the bipolar plate 10 are attached together, for example by welding or gluing. For example, the peripheral regions 102 and 102' abut against each other in the stacking direction X. If necessary, welding or gluing can be performed along the peripheral regions 102 and 102' around the entire periphery of the bipolar plate 10.

[0147] Since the chemical reaction between the reactant fluids at the membrane 204 is exothermic, it may be desirable to cool the battery. To this end, preferably at the rear of the flow fields 103 and 103', the plates 100 and 100' of the bipolar plate 10 define a flow field 13 between them in the stacking direction X, which is inside the bipolar plate 10 for cooling the fluid. Where appropriate, the welding or bonding between the peripheral regions 102 and 102' provides a seal between the flow field 13 and the outside of the bipolar plate 10, thereby forming a closed loop surrounding the flow field 13. Preferably, the flow field 13 is supplied with a cooling fluid through one of the openings 101 in the plates 100 and 100' (in this case, one of the openings 101c). The cooling fluid is discharged through another opening 101c. The other openings 101a and 101b are sealed from the flow field 13 so that no reactant fluid can enter the flow field 13. For example, the cooling fluid flows in the longitudinal direction Y from one opening 101 c to the other opening via the flow field 13 .

[0148] Figure 6 and Figure 7 A second embodiment is presented which, except for the differences indicated below, is identical to Figures 1 to 5 The same as the first embodiment shown in FIG. Figures 1 to 5 as well as Figure 6 and Figure 7 , the same reference numerals are used to denote the same features between the two embodiments. Figure 6 and Figure 7 In the embodiment, the reference numeral 200 is added to indicate the same as for Figure 1 and Figure 5 The following description focuses on the corresponding but different features. Figure 6 and Figure 7 Examples and Figures 1 to 5 The differences between the embodiments are not described in detail, and the same features or features based on the same principles are not described in detail.

[0149] exist Figure 6 and Figure 7 In the embodiment shown, the peripheral portion 202 of the MEA 200 is advantageously replaced by a peripheral portion 402. The peripheral portion 402 is preferably not formed by a retaining frame, but by a peripheral continuation 406 that extends the membrane 204 parallel to the plane P. In this embodiment, the peripheral continuation 406 and the membrane 204 preferably form a single integral membrane that forms both the central portion 203 and the peripheral portion 202 of the MEA 200.

[0150] Additionally, and independently of the presence of the peripheral continuation 406 or alternatively the peripheral portion 402, for Figure 6 and Figure 7In this embodiment, first peripheral seal 500 replaces first peripheral seal 300. First peripheral seal 500 includes a main body portion 301 identical to seal 300. Fins 302 of seal 300 are replaced by fins 502 of seal 500. Each fin 502 includes a joint portion 304 identical to the joint portion of fin 302, a middle portion 305 identical to the middle portion of fin 302, and an end portion 506 that replaces the end portion 306 of fin 302.

[0151] Like end portion 306, end portion 506 is interposed in stacking direction X between: the gas diffusion layer 205 and the peripheral continuation 406, on the one hand, and the peripheral region 102, on the other. End portion 506 is attached to the middle portion 305. End portion 506 is a straight line. Unlike end portion 306, its projection onto principal plane P is tilted relative to the longitudinal direction Y, such that end portion 506 extends the middle portion 305 in alignment with the middle portion 305. Thus, the assembly consisting of the middle portion 305 and end portion 506 is a straight line, and its projection onto principal plane P is tilted relative to the longitudinal direction Y. End portion 506 includes a contact portion 507. Contact portion 507 corresponds to the portion of end portion 506 interposed in stacking direction X between the gas diffusion layer 205 and the peripheral region 102.

[0152] Therefore, according to Figures 6 and 7 In the embodiment shown in FIG, each fin 502 has an extension trajectory that forms substantially a comma in a direction from the main body portion 301 toward the flow field 103 .

[0153] exist Figure 6 and Figure 7 In the illustrated embodiment, a second peripheral seal 500' preferably replaces the second peripheral seal 300'. Peripheral seal 500' includes the same main body portion 301' as seal 300'. On the other hand, fin 302' of seal 300' is replaced by fin 502' of seal 500'. Fin 502' includes the same joining portion 304' as fin 302', the same intermediate portion 305' as fin 302', and includes an end portion 506' that replaces the end portion 306' of fin 302'. The same characteristics as described above for portions 304, 305, 506 and 507 of fin 502 apply mutatis mutandis to portions 304', 305', 506' and 507' of fin 502'.

[0154] for Figure 6 and Figure 7 In this embodiment, the anode 100' and cathode 100 plates are connected Figures 1 to 5The plates provided in are identical or have a similar construction, except that they are not attached to each other by welding or gluing, but lie against each other in the stacking direction X without being attached to each other.

[0155] More precisely, independently of the shape of the fin and independently of the presence of the peripheral continuation 406 or, alternatively, the presence of the peripheral portion 402, Figure 6 and Figure 7 The plates 100 and 100', respectively belonging to two adjacent cells 2, abut against each other via a plate seal 211, which is interposed between the plates 100' and 100, respectively belonging to the two adjacent cells, in the stacking direction X. Plate seal 211 includes a main portion 212, which is interposed between the peripheral regions 102 and 102' along the stacking direction X and forms a closed loop surrounding the flow field 13 to prevent cooling fluid from leaking between the flow field 13 and the outside of the bipolar plate 210 formed by the plates 100, 100', and the plate seal 211. Similar to seals 300, 300', 500, and 500', seal 211 also includes fins 213 extending from the main portion 212 toward the flow field 13 along the transverse direction Z. Fins 213 are arranged between the plates 100 and 100' along the stacking direction X. The fins 213 are used to ensure that the coolant flows substantially between the flow fields 103 and 103 ′ rather than between the peripheral areas 102 and 102 ′, thereby improving cooling efficiency.

[0156] Figure 8 A third embodiment is presented which, except for the differences indicated below, is identical to Figures 1 to 5 The same as the first embodiment shown in FIG. Figures 1 to 5 as well as Figure 8 , the same reference numerals

[0157] Used to indicate the same features as above. Figure 8 In the embodiment shown in FIG. 400, an increase of

[0158] The reference numerals are used to indicate Figure 1 and Figure 5 The following description focuses on the corresponding but different features. Figure 8 The embodiment shown in Figures 1 to 5 The differences between the embodiments shown in FIG. 1 and FIG. 2 are not specifically described, and identical features or features based on the same principles are not described in detail.

[0159] exist Figure 8 In the illustrated embodiment, first peripheral seal 300 is replaced by first peripheral seal 700 , which includes a body portion 301 identical to the body portion of seal 300 and fins 702 instead of fins 302 .

[0160] Each fin 702 has a joining portion 704 that replaces the joining portion 304, an intermediate portion 305 that is identical to the intermediate portion of the fin 302, and an end portion 306 that is identical to the end portion of the fin 302. The joining portion 704 extends from the main body 301 starting from the inner longitudinal surface 303. Like the joining portion 304, the joining portion 704 is a straight line. However, unlike the joining portion 304, the projection of the joining portion 704 on the main plane P is inclined relative to the longitudinal direction Y. The intermediate portion 305 is attached to the joining portion 704 and is aligned with the joining portion 704. Therefore, the assembly consisting of the joining portion 704 and the intermediate portion 305 is a straight line, and its projection on the main plane P is inclined relative to the longitudinal direction Y.

[0161] Figure 9 and Figure 10 A fourth embodiment is presented which, except for the differences indicated below, is identical to Figures 1 to 5 The same as the first embodiment shown in FIG. Figures 1 to 5 as well as Figure 9 and Figure 10 , the same reference numerals are used to denote the same features as those described above. The following description focuses on Figure 9 and Figure 10 Examples and Figures 1 to 5 The differences between the embodiments are not described in detail, and the same features or features based on the same principles are not described in detail.

[0162] exist Figure 9 and Figure 10 In the embodiment shown, the peripheral portion 202 of the MEA 200 is provided with Figure 6 and Figure 7 The embodiment shown in FIG. 4 is described with reference to the peripheral portion 402 of the peripheral extension 406. Figure 9 and Figure 10 In the embodiment, the anode 100' and cathode 100 plates are connected with Figures 1 to 5 The plates provided in the embodiment are identical or have a similar construction, except that the two anode 100' and cathode 100 plates, respectively belonging to two adjacent cells, are not attached to each other by welding, but rather they abut against each other in the stacking direction X without being attached to each other, with the above-mentioned Figure 6 The plate seal 211 is described in the embodiment.

[0163] Figure 11 A fifth embodiment is shown, which, except for the differences indicated below, is identical to Figures 1 to 5 The same as the first embodiment shown in FIG. Figures 1 to 5 as well as Figure 11 , the same reference numerals are used to denote the same features as those described above. Figure 11In the embodiment shown in FIG, the reference numerals increased by 600 are used to indicate the same Figure 1 and Figure 5 The following description focuses on the corresponding but different features. Figure 11 The embodiment shown in Figures 1 to 5 The differences between the embodiments shown in FIG. 1 and FIG. 2 are not specifically described, and identical features or features based on the same principles are not described in detail.

[0164] exist Figure 11 In the illustrated embodiment, seal 300 is replaced by seal 900 having a main body portion 301 identical to the main body portion of seal 300. However, fin 302 has been replaced by fin 902. Fin 902 includes a junction portion 904 replacing junction portion 304, a middle portion 905 replacing middle portion 305, and an end portion 906 replacing end portion 306. These portions 904, 905, and 906 continue from main body portion 301 in the direction of flow field 103.

[0165] In general, the fin 902 is meandering along an axis parallel to the transverse direction Z.

[0166] The fin 902 is attached to the inner longitudinal surface 303 of the main body portion 301 via a joint portion 904. Rather than being a straight line like the joint portion 304, the joint portion 904 is curved, and its projection onto the principal plane P is curved relative to the longitudinal direction Y. Thus, at least a portion of the joint portion 904 is skewed relative to the main body portion 301 in its projection onto the plane P.

[0167] The intermediate portion 905 is attached to the joining portion 904. Rather than being a straight line like the intermediate portion 305, the intermediate portion 905 is curved, and its projection onto the principal plane P is a curve. The intermediate portion 905 is skewed relative to the main portion 301 in its projection onto the plane P, and is preferably oriented so as to be inversely skewed relative to the joining portion 904.

[0168] End portion 906 is attached to middle portion 905 and terminates fin 302. End portion 906 is interposed in stacking direction X between gas diffusion layer 205 and retaining frame 206, on the one hand, and peripheral region 102, on the other. Unlike end portion 306, which is rectilinear, end portion 906 is curved, and its projection onto main plane P is curved relative to longitudinal direction Y. End portion 906, in its projection onto plane P, is tilted relative to main portion 301 and is preferably oriented so as to be tilted in the opposite direction relative to middle portion 905.

[0169] The end portion 906 includes a contact portion 907 that can be compared with the above-described contact portion 307. The contact portion 907 corresponds to a portion of the end portion 906 that is interposed between the gas diffusion layer 205 and the outer peripheral region 102 in the stacking direction X.

[0170] Figure 12 and Figure 13 A sixth embodiment is presented, which, except for the differences indicated below, is identical to Figure 9 and Figure 10 The same as the fourth embodiment shown in FIG. Figure 12 and Figure 13 , the same reference numerals are used to denote the same features as those described above. Figure 12 and Figure 13 The embodiment of the present invention is shown in FIG. 800, which is a reference numeral used to indicate the embodiment of the present invention. Figure 1 and Figure 5 The following description focuses on the corresponding but different features. Figure 12 and Figure 13 Examples and Figure 9 and Figure 10 The differences between the embodiments are not described in detail, and the same features or features based on the same principles are not described in detail.

[0171] exist Figure 12 and Figure 13 In the illustrated embodiment, first peripheral seal 300 is replaced by first peripheral seal 1100. First peripheral seal 1100 includes a main body portion 301 identical to that described above. Seal 1100 includes fin 1102 in place of fin 302. Fin 1102 has a joint portion 1104 in place of joint portion 304, a middle portion 305 identical to the middle portion of fin 302, and end portions 306 identical to the end portions of fin 302.

[0172] The joining portion 1104 differs from the joining portion 304 only in that it comprises an opening 1105 in the form of a notch in the fin 1102, which separates the joining portion 304 from the peripheral portion 402. To form this opening 1105, the thickness of the joining portion 1104 measured in the stacking direction X is smaller than the thickness of the intermediate portion 305 measured in the stacking direction X. This opening 1105 in the longitudinal direction Y allows a fluid to flow through the fin 1102, for example in order to drain reaction products or condensation that may form between consecutive fins 1102.

[0173] exist Figure 12 and Figure 13In the illustrated embodiment, the second peripheral seal 300' is replaced by a peripheral seal 1100'. Peripheral seal 1100' includes a main body portion 301' identical to that described above. Peripheral seal 1100' includes a fin 1102' that replaces fin 302'. Fin 1102' has a joint portion 1104' that replaces joint portion 304', a middle portion 305' that is identical to the middle portion of fin 302', and end portions 306' that are identical to the end portions of fin 302'. Joint portion 1104' forms an opening 1105' based on the same principle as opening 1105 of joint portion 1104.

[0174] Figure 14 A seventh embodiment is presented, which, except for the differences indicated below, is identical to Figure 12 and Figure 13 The same as the embodiment shown in Figure 14 In the same reference numerals are used to denote the same features as those described above. Figure 14 In the embodiment shown in FIG, the reference numerals increased by 200 are used to represent Figure 12 and Figure 13 The following description focuses on the features described in Figure 14 The differences between the embodiment described in the specification and its previous embodiments are not described in detail, and the same features or features based on the same principles are not described in detail.

[0175] exist Figure 14 In the embodiment shown, the peripheral seal 1100' is Figure 8 The peripheral seal 700 shown in FIG. 7 is replaced, and the plate seal 211 is replaced by the plate seal 411 .

[0176] Plate seal 411 includes a main body portion 212 that is identical to the main body portion of seal 211. In a similar manner to seal 211, seal 411 also includes fins 413 that replace fins 213. Fins 413 differ from fins 213 in that they have recesses 414 that operate according to the same principle as openings 1105 to allow cooling fluid to flow through fins 413.

[0177] Figure 15 An eighth embodiment is presented, which, except for the differences described below, is identical to Figures 1 to 5 Same as the first embodiment. Figure 15 In the following description, the same reference numerals are used to denote the same features as those described above. Figure 15 The embodiment shown in Figures 1 to 5 The differences between the embodiments shown in FIG. 1 and FIG. 2 are not specifically described, and identical features or features based on the same principles are not described in detail.

[0178] In addition to already targeted Figures 1 to 5In addition to all the elements described in the embodiments, Figure 15 The embodiment of the present invention provides a dam 310 that extends parallel to the main body 301 of the seal 300, i.e., parallel to the longitudinal direction Y. The dam 310 is interposed between the peripheral region 102 and the diffusion layer 205 along the stacking direction X. The dam 310 is arranged between the flow field 103 and the seal 300 in the transverse direction Z. The dam 310 advantageously connects all or some of the fins 302 together, with the respective end portion 306 of each fin 302 or at least one of the plurality of fins 302 being attached to the dam 310. Preferably, the dam 310 is made of the same material as the seal 300, so that it can be formed at the same time, from the same material, and / or from the same components as the seal 300.

[0179] Because weir 310 abuts flow field 103, it is intended to define channels 295, which are preferably added to channels 105 and have the same function as these channels 105. Channels 295 are bounded in stacking direction X by peripheral region 102, which performs the same function as channel base 1051 of channels 105, and layer 205. Thus, channels 295 are bounded in transverse direction Z by channel teeth 1052 of cathode plate 100, and by weir 310 adjacent and parallel to these channel teeth 1052, which can be referred to as the last channel tooth. Therefore, additional channels 295 are preferably designed to direct the flow of reactant fluids relative to the active area of ​​MEA 200, which is central portion 203 of MEA 200, within which membrane 204 has access to the reactant fluids flowing in the flow field. The presence of the dam 310 makes it possible to simplify the construction of one or more fins 302 attached to the dam 310, so that they extend laterally beyond the entire lateral dimension between the main body 301 of the peripheral seal 300 and the dam 310, thus spanning the entire bypass area 40 to form an additional channel (here, channel 295) for guiding the flow of the reactant fluid. This is particularly advantageous if the channel teeth 1052 of the flow field 103 are made by stamping the cathode plate 100 made of metal. In this case, it may be complicated to produce the fin 302 made of a molded polymer material, especially using the same material and production method as the peripheral seal 300, so that it contacts the last pressed metal tooth. In this case, the presence of the dam 310 means that the last channel tooth in the active area is not stamped, but is formed by a tooth of the same material as the peripheral seal 300 and the fin 302, so that they form a single unit.

[0180] Therefore, in Figure 15In the example shown, the dam 310 is located opposite the central portion 203 of the MEA 200 at its boundary with the peripheral portion 202 in the stacking direction X, such that the channel 295 is opposite the central portion 203. In other words, along the transverse direction Z, the dam 310 is offset toward the inside of the cell relative to the inner periphery of the holding frame 206, at which the holding frame 206 clamps the membrane 204.

[0181] Figure 16 and Figure 17 A ninth embodiment is presented, which, except for the differences described below, is identical to Figure 15 The same as the eighth embodiment.

[0182] In this embodiment, the Figure 15 The same reference numerals are used. Figure 16 and Figure 17 In this embodiment, Figure 15 Compared to the dam-shaped member 310 in FIG, the dam-shaped member 310 is offset toward the outside of the battery 2 in the transverse direction Z. In other words, Figure 16 and Figure 17 The dam-shaped member 310 is opposite the boundary between the peripheral portion 202 and the central portion 203 in the stacking direction X, that is, opposite the inner periphery of the frame 206 that holds the central portion 203. Therefore, the channel 295 faces a portion of the central portion 203 that extends directly along the edge of the frame 206. In this case, the goal is to position the dam-shaped member 310 as close as possible to the last channel tooth in the transverse direction Z.

[0183] The channel 295 defined by the dam 310 is not necessarily the same size as the channel 103 and is particularly Figure 16 and Figure 17 and one can try to minimize its size, especially in the lateral direction Z.

[0184] In a variant not shown, the fins of the first peripheral seal 300, 500, 700, 900, 1100 may not be opposite the fins of the second peripheral seal 300', 500', 1100', but may be offset from one another in the longitudinal direction Y. According to other variants not shown, the same first peripheral seal 300, 500, 700, 900, 1100 or the second peripheral seal 300', 500', 1100' may comprise fins of different shapes, and the first peripheral seal 300, 500, 700, 900, 1100 may have different fins than the second peripheral seal 300', 500', 1100'.

[0185] Any feature described with respect to one embodiment or variant can be implemented in any of the other described embodiments and variants. In particular, any fin and any body portion of a peripheral seal or plate seal can be used with any of the other peripheral seals or plate seals described above. Dam 310 can be applied to any of the aforementioned peripheral seals or plate seals. In particular, the fins can include both curved and straight portions.

Claims

1. A peripheral seal (300; 500; 700; 900; 1100) for a cell (2) of a fuel cell (1), the peripheral seal (300; 500; 700; 900; 1100) comprising: A main body portion (301) configured to be interposed between: a peripheral region (102) of a plate (100) belonging to the battery (2), the plate (100) extending parallel to a main plane (P) of the battery (2), the main plane (P) being perpendicular to the stacking direction (X), the plate (100) comprising a flow field (103) for a reactant fluid surrounded by the peripheral region (102), and a peripheral portion (202; 402) belonging to a membrane electrode assembly (200), said membrane electrode assembly further comprising at least one gas diffusion layer (205), at least one fin (302; 502; 702; 902; 1102), the at least one fin comprising a joining portion (304; 704; 904; 1104), the fin (302; 502; 702; 902; 1102) being connected to the main body portion (301) via the joining portion; Characterized in that the at least one fin (302; 502; 702; 902; 1102) further comprises: terminating an end portion (306; 506; 906) of the fin (302; 502; 702; 902; 1102), the end portion being configured to be interposed between the gas diffusion layer (205) and the peripheral region (102) in the stacking direction (X), and · connecting the joining portion (304; 704; 904; 1104) to an intermediate portion (305; 905; 1105) of the end portion (306; 506; 906), the intermediate portion (305; 905; 1105) being configured to be tilted relative to the main portion (301) of the peripheral seal (300; 500; 700; 900; 1100) in a projection onto the main plane (P).

2. The peripheral seal (300; 500; 700; 900; 1100) according to claim 1, comprising a plurality of fins (302; 502; 702; 902; 1102), each fin (302; 502; 702; 902; 1102) being connected to the main body portion (301) only via the joining portion (304; 704; 904; 1104).

3. The peripheral seal (300; 500; 700; 900; 1100) according to any one of the preceding claims, wherein The engaging portion (304; 1104) is configured to extend perpendicularly to the main body portion (301) when projected onto the main plane (P).

4. The peripheral seal (300; 500; 700; 900; 1100) according to any one of the preceding claims, wherein The end portion (306) is configured to extend perpendicularly to the main portion (301) when projected onto the main plane (P).

5. Peripheral seal (300; 500; 700; 1100) according to any one of the preceding claims, wherein At least one of the end portion (306; 506), the middle portion (305; 1105) and the joining portion (304; 704; 1104) is configured to be a straight line when projected onto the main plane (P).

6. The peripheral seal (900) according to any one of the preceding claims, wherein A portion of the fin (902) is configured to be curved in projection onto the principal plane (P).

7. The peripheral seal (1100) according to any one of the preceding claims, wherein The engagement portion (1104) includes an opening (1105) that allows fluid to flow through the fin (1102).

8. Peripheral seal (300; 500; 700; 900; 1100) according to any one of the preceding claims, wherein The main body (301) of the peripheral seal (300; 500; 700; 900; 1100) and the fin (302; 502; 702; 902; 1102) are formed as a whole.

9. The peripheral seal (300) according to any one of the preceding claims, further comprising a dam (310) parallel to the main body portion (301), The dam-shaped member (310) connects the end portions (306) of the plurality of fins (302), The dam (310) is formed as a whole with the first peripheral seal (300) and is configured to be interposed between the gas diffusion layer (205) and the electrode plate (100) along the stacking direction (X).

10. A cell (2) for a fuel cell, comprising a plate (100) and a peripheral seal (300; 500; 700; 900; 1100) according to any one of the preceding claims, the plate (100) comprising: the peripheral region (102), and • The flow field (103) for the reactant fluid surrounded by the peripheral region (102).

11. The battery (2) according to claim 10, further comprising: The membrane electrode assembly (200), which extends parallel to the main plane (P) of the battery (2), is superimposed on the first electrode plate (100) in the stacking direction (X), and comprises: the peripheral portion (202; 402), said peripheral portion being opposite to said peripheral region (102) in said stacking direction (X), a central portion (203), said central portion comprising a polymeric proton exchange membrane (204), The side is the peripheral portion (202; 402), and the at least one gas diffusion layer (205), the at least one gas diffusion layer being interposed between the polymer proton exchange membrane (204) and the electrode plate (100) in the stacking direction (X), The peripheral seal (300; 500; 700; 900; 1100) provides: a seal against the reactant fluid between: on the one hand, a bypass region (50) of the cell (2), the bypass region (50) being defined inside the cell (2) between the peripheral portion (202; 402) of the membrane electrode assembly (200) and the peripheral region (102), and on the other hand, a region (3) outside the cell (2), the region (3) being outside the main portion (301) and opposite the bypass region (50); and The at least one fin extends into the bypass region.

12. The battery (2) according to claim 11, wherein A contact portion (307; 507; 907) of the end portion (306; 506; 906) is compressed between the gas diffusion layer (205) and the peripheral region (102).

13. The battery (2) according to any one of claims 10 to 12, wherein: The flow field (103) defines a plurality of channels (105) for the flow of the reactant fluid, the channels (105) extending in a longitudinal direction (Y) perpendicular to the stacking direction (X), each channel (105) being defined by: a channel bottom (1051) belonging to the flow field (103) and extending parallel to the longitudinal direction (Y), and Two channel teeth (1052) belonging to the flow field (103) and extending parallel to the longitudinal direction (Y), the channel teeth (1052) being arranged on both sides of the channel bottom (1051) and protruding relative to the channel bottom (1051), each channel tooth (1052) being in contact with the gas diffusion layer (205) in the stacking direction (X).

14. The battery (2) according to claim 13, wherein The channel teeth (1052) also protrude from the peripheral region (102) in the stacking direction (X).

15. A fuel cell (1) comprising cells (2), at least one of the cells (2) being a cell according to any one of claims 10 to 14, the cells (2) being stacked along the stacking direction (X) to form a stack.

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